.page-bottom {
  display: flex;
  width: 100%;
  height: 40px;
  position: fixed;
  text-align: center;
  line-height: 40px;
  background-color: #fff;
  bottom: 0;
  z-index: 1000000;
}
.page-bottom .pre {
  flex-grow: 1;
}
.page-bottom span {
  flex-grow: 1;
}
.page-bottom .next {
  flex-grow: 1;
}
